I’ve been trying to put a name to the feeling that’s mine right now – and all of London’s. Not to big myself up, or minimise the impact of London 2012 and the phenomenal achievements of the Olympians and Paralympians. But there’s something in the air that I’ve been trying to feel, own, and put into words. Without sounding ungrateful. Or like a next-project-obsessed workaholic.

Even the best parties have to come to an end.

OK, so I may be both of those things. At times. But this feeling is like the puckered balloons the day after a mega party. The dust-covered peanuts you find down your sofa weeks after a dinner party. And the sense of having loved (all the guests) and then lost (when they all leave) when you’ve worked so hard and wanted to make every detail a winning, talked-about one. Which parties generally are, and they certainly were for the million people I had to say ‘excuse me’ to, on a way to a meeting through central London at lunchtime yesterday. A million people lined the streets to salute the London 2012 stars.

But my individual deflated feeling, in the midst of all this post-Olympic partying, started with the certificate arriving for my MA. My Masters in Creative Writing. The accolade I’d sweated for, done many all-nights for, worked five years for. I’d done it part time, as something for me. I didn’t need an MA for any career reasons. I make my living as a writer, and have done for 16 years. So this was for me, not for the accolade. It wasn’t a medal, as such, but a printed record of my achievement.

Except that, when it arrived, my MA may as well have been a certificate from my home  insurance company confirming my cover for the next year. There were no flourishes, no twists and no exciting drama that I had for my first degree. No fancy hieroglyphics. No stylish font. Just a plain old typed-out certificate. Except, in my heart of hearts, even it it had had all the bells and whistles, I’m not sure I would have felt any better towards it.

I felt bereft. The certificate was confirmation that something important was over. I put it to one side, wondering how to honour it in some way. But not now.

How I think my own feelings are tapping into the collective unconscious right now is that there is also this sense among Londoners that there will never be a party like London 2012 ever again. Not on this scale, anyway. Double Gold Medal winning Mo Farah summed it up in his comments when he said that the heroes’ victory parade of all the winners was “bitter sweet” and he may never have that many people chanting his name again. All that work. All those medals. And now? Now what..?

As I said, I’d been hunting for the right words to express this uncomfortable feeling. And then, serendipitous as ever, I found it on Twitter via the marvellous Dr Alice Chan.

She quotes Maya Angelou saying: “Achievement brings its own anticlimax.”

Five words sum up, so simply, the feeling I’ve been searching to name. And everyone in London who has been touched by the Games, I am sure, will get what those words mean.